Better Brakes & Steering for Our TJ WranglerPosted in How To: Suspension Brakes on August 12, 2019
Disclaimer: Editor Hazel and Tech Editor Simons are longtime Jeep guys and warned us that this project would become far more involved than we anticipated. While we are pleased with the final product, it was hardly a bolt-on affair. We had to source parts from multiple vendors and do significant fabrication. If you just want stronger steering, there are bolt-on options that fit the bill. If you want to replace the inverted Y setup, there are even kits that do that, but they are expensive and you don't get larger brakes. It all comes down to your priorities.
The introduction of the TJ Wrangler in 1997 offered many advantages over the outgoing YJ, most notably the front and rear coil suspension. The subsequent Rubicon model that began in 2003 set the bar even higher with locking differentials and a 4:1 transfer case. What was sorely lacking, however, was adequate steering. The TJ uses an inverted Y steering configuration with a drag link that connects from the pitman arm to the passenger knuckle and a puny tie rod from the drag link to the driver knuckle. Furthermore, there's a bend in the passenger-side drag link to provide clearance when turning full-lock. And guess where the factory-style tubing always fails. You guessed it—at the bend.
Jeep used a separate drag link and tie rod on WJ Grand Cherokees though, and these vehicles are abundant in junkyards across the country. As an added benefit, WJs also use brakes with larger-diameter rotors and better calipers than TJs, a worthwhile upgrade when running big tires. While no one offers a complete kit for the WJ knuckle conversion, JKS Manufacturing does offer parts to complete this conversion, such as the knuckle flange spacer, axle-side track bar bracket, and track bar. JKS's Justin Mclean was instrumental in providing us with not only the right parts but also the information we needed in order to perform the conversion. The parts that JKS doesn't offer were sourced from Barnes 4WD, Skyjacker, WFO Concepts, and Powerstop. The parts combine to provide three benefits: stronger steering, shorter stopping distances, and improved suspension geometry.
Starting with the steering, the original TJ tie rod is only 0.88 inch in diameter with a wall thickness less than 0.125 inch thick. We built a new tie rod and drag link from 1.5x0.250-wall DOM tubing and fitted it with QA1 threaded tube bungs we sourced from Summit Racing Equipment. These allowed us to run GM tie-rod ends we sourced from WFO Concepts that use a big 7/8-inch shank. While you can upgrade your TJ steering without adding WJ knuckles, another huge benefit is the better brakes. WJs use rotors that are a full inch larger in diameter, as well as being equipped with dual-piston calipers. While you can use the rotors, pads, and brake lines from the donor vehicle, we replaced the rotors and pads with new parts from Powerstop. The rotors do have to be redrilled from the WJ's 5-on-5 bolt pattern to 5-on-4 1/2, which is another reason to purchase new rotors if you are putting in this effort anyway.
While raising the drag link location reduces the change in angle as the suspension cycles, it won't do you any good if the track bar is not parallel to the drag link. JKS Manufacturing sells a bracket for the frame side to raise the track bar 4 inches to match the drag link. The other issue with the frame-side mount is that it uses a tie-rod end rather than a bushing. These tie-rod ends are weak, prone to wear, and limit the amount of suspension movement. We cut the factory bracket off the frame (no going back now!) and added a Barnes bracket on the outside of the frame that increased the length by 2 inches and converted the end to a bushing. JKS Manufacturing's DIY track bar spanned the distance between the two brackets, but by putting the bracket on the outside of the frame we ran into interference between the track bar bracket and factory sway bar. For now, we are running without a sway bar, but we plan to address that soon.
While we were swapping the knuckles, we also took the opportunity to replace our ball joints. This is not a requirement since the ball joint is fitted in the end forging on a Wrangler and not in the knuckle (as it is on, say, a Super Duty), but it is a good time to upgrade or replace your ball joints. We added Skyjacker's Rock Ready ball joints to our Dana 44 front axle. You probably think of Skyjacker as a suspension company, but it makes a host of other products, from brake lines to skidplates to, yes, ball joints. These ball joints are made in the USA and feature tapered roller bearings, are greasable, and use a powdered metal bearing instead of the factory plastic bearing. Yes, plastic! The Skyjacker ball joints all use an innovative design that distributes the load between the upper and lower ball joints for improved load carrying capacity, longer service life, and greater overall strength. We don't anticipate having to do any more for years to come than grease the ball joints.
After the conversion was completed, we were rewarded with a Jeep that worked significantly better on the street and on the trail. The improvement in braking is significant to the point where we had to adapt our braking habits or else we lock up the tires. The handling is much better as well, with geometry that is even better than the factory TJ offered. Cornering produces nearly no body roll, even with the sway bar disconnected. These were ancillary benefits in our search to upgrade our steering, but they end up being benefits that we appreciate every time we drive our Wrangler. While the installation was far from bolt-on, as the saying goes, "The juice was worth the squeeze."
Here's the not-so-short rundown on what it takes to convert your 1984-2006 Jeep's Dana 30 to WJ knuckles for high steer.
WJ Grand Cherokee knuckles
WJ Grand Cherokee brake caliper brackets
WJ Grand Cherokee brake calipers (and hardware)
JKS WJ steering knuckle spacer, PN OGS930 x2
JKS Fab front track bar, PN OGS951
JKS Fab fab front track bar bracket, PN OGS920
Barnes frame side track bar bracket, PN B4W250149-1
QA1 RH tube adapter, PN 1844-132 x2
QA1 LH tube adapter, PN 1844-131 x2
GM RH tie-rod end, PN ES2010R
GM LH tie-rod end, PN ES2010L
Offset RH tie-rod end, PN EX23434R
Offset LH tie-rod end, PN EX23434L
Skyjacker Rock Ready ball Joints, PN JD302B
Powerstop brake rotors, PN AR8742XPR
Powerstop Z36 brake pads, PN Z36-935